aithy: Skill for Claude Code

.claude/skills/ax-playbook/SKILL.md

ax-playbook is a skill for Claude Code from dosco/aithy. It costs 70 tokens per session (1,811 once invoked), scanned A, original, Apache-2.0.

A reference for using playbooks in the @ax-llm/ax TypeScript library. A playbook is a body of task knowledge that can grow from examples and be added to a program's context.

In plain words
What is it for?
It is for growing reusable task guidance offline or from live feedback, applying that guidance to programs or agents, inspecting it, and saving it for later use.
Why use it?
It provides the correct patterns for improving task knowledge from feedback, saving and restoring it, and applying it to generators or agents. This avoids treating evolving context as ordinary prompt text.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is dosco/aithy's own configuration. It tells Claude Code how to work on aithy itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything aithy configures →

Reuse

Borrowing it

Nothing to install: this file belongs to dosco/aithy. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/dosco/aithy/main/.claude/skills/ax-playbook/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/dosco/aithy

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ax-playbook

README.md
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<a href="https://agentmods.dev/skills/dosco/aithy/ax-playbook"><img src="https://agentmods.dev/badge/skills/dosco/aithy/ax-playbook.svg" alt="Measured on agentmods" height="20"></a>
Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,811 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00070 $0.01811
Opus 5 $0.00035 $0.00905
Sonnet 5 $0.00014 $0.00362
Haiku 4.5 $0.00007 $0.00181

Measured 4d ago against content hash 23c83109dd81, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

ax-playbook scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/ax-playbook/SKILL.md · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Playbook Codegen Rules (@ax-llm/ax)

Use this skill to generate context-playbook code. A playbook grows an evolving body of task knowledge and renders it into a program's context. The evolution engine (ACE — Agentic Context Engineering) is hidden behind playbook(...), exactly as optimize(...) hides its optimizer. Prefer the playbook(...) concept; only reach for AxACE directly when the user explicitly wants the low-level engine.

Use These Defaults

  • Create with playbook(program, { studentAI, teacherAI? }); it returns an AxPlaybook handle.
  • Grow offline with await pb.evolve(examples, metric) — returns { bestScore, playbook }.
  • Grow online with await pb.update({ example, prediction, feedback }) — no metric needed.
  • Apply with pb.applyTo(program) (defaults to the bound program).
  • Persist with pb.toJSON() and restore with playbook(program, opts).load(snapshot).
  • Inspect with pb.render() (markdown) and pb.getState() ({ playbook, artifact }).
  • For agents use agent.playbook({ target: 'actor' | 'responder' }); default target is 'actor'.
  • Use a cheaper studentAI to run the program and an optional stronger teacherAI to reflect/curate.
  • Prefer ai(), ax(), and agent() for new code.

Critical Rules

  • playbook(...) binds to an AxGen program; evolve/update need that program's signature.
  • evolve() returns only { bestScore, playbook }. There is no Pareto front and no optimizedProgram — that is optimize(...)'s shape, not a playbook's.
  • update({ example, prediction, feedback }) requires the full { example, prediction }; example must match the program's input fields (plus any expected output). Do not pass bare input fields at the top level.
  • update() works without a prior evolve()/load() — the handle hydrates lazily on first use.
  • applyTo() injects a ## Context Playbook block into the program description; calling it repeatedly recomposes from the original base (no stacking).
  • Keep the offline metric deterministic and cheap, like a GEPA metric.
  • A playbook is plain JSON. Persist pb.toJSON() and load(...) it into a fresh program for production.
  • The playbook engine, construction-time agent attachment, failure harvesting, and verified agent evolution are available in TypeScript and the generated Python, Java, C++, Go, and Rust packages. Use each package's native casing and callback types.

Read the full file on GitHub · 126 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago Changed · +30 lines 23c83109dd81
  2. 9d ago First seen · 96 lines · 70 tokens per session scan A 6c3ccac210aa

Subscribe to this mod's changes

ax-playbook is a skill published in the GitHub repository dosco/aithy (107 stars, last pushed 7d ago), licensed Apache-2.0. It adds 70 tokens to every session and 1,811 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.